# What is the balance point between 2 gravitational bodies called?

1. Aug 11, 2014

### fosterboy123

Hi there!

My physics is not exactly strong (I am a games developer/designer).

Basically I have a game idea where the player will jump between the floor and the ceiling. At any point the player will jump and be affected by the gravitational point of the ceiling and the floor at the same time based on their position on the Y axis.

I understand the mathematics, but I am curious to if there is a name for the point at which the two gravitational forces are in balance (assuming both gravitational forces are identical in strength). I.e. is there a name for the point where the player would just float, not moving toward the ceiling nor the floor?

Thanks

2. Aug 11, 2014

### jaydnul

Maybe point of equilibrium?

But I think it would be difficult, at least in real life, to sit directly at the point of zero net gravitational force. A fraction of an inch too far in either direction will pull you away.

Unless the room is spherical, then everywhere would have net zero gravitational force.

3. Aug 11, 2014

### fosterboy123

Yeah, I think Equilibrium sounds right!

I actually wanted to know simply for the name and I had no idea what it was called.

Thank you very much!

4. Aug 11, 2014

### 94JZA80

"Lagrange point" or " Lagrangian point" is the term you're looking for...

5. Aug 11, 2014

### A.T.

Not really. Lagrange point 1 is not where the gravity forces of two bodies cancel completely, but rather where their net effect provides exactly the centripetal force needed to stay in line with the two bodies, while they orbit:

http://en.wikipedia.org/wiki/Lagrangian_point#L1

6. Aug 11, 2014

### 94JZA80

my mistake...i didn't realize that the OP was looking for a point or region in which gravitational forces cancel completely. I guess I need to read more carefully first, b/c after having read the OP again, a stationary floor and ceiling scenario doesn't exactly work like actual orbiting bodies...

...in this case, i don't know that there is any better a term for this kind of cancelling of gravitational forces than simple equilibrium as suggested before i initially posted.